1. Field of the Invention
The present invention relates to a filmless sticker for transfer-printing an ink in a pattern and/or characters thereon to a receiver, as well as to a process for preparing the filmless sticker which is easily achieved and improves the integrated appearance of the sticker with low cost but high efficiency.
2. Description of the Prior Arts
Transfer-printing is a well known printing process, in which ink is transferred from a transfer-printing sheet or sticker to a receiving article, flat or not, by pressure and/or heat to form a pattern and/or characters on the receiver, and then the transfer-printing sheet is separated from the receiver after transfer-printing in direct contact with each other. Similar transfer-printing sheets disclosed in the related applications of the inventor, U.S. Ser. No. 08/806,087 (1997) nou U.S. Pat. No. 5,876,839, and U.S. Pat. No. 5,453,155 (1995), are incorporated herein for reference.
A conventional process for preparing a transfer-printing sheet or sticker is illustrated in FIG. 1. A cross-section of a conventional transfer-printing sheet or sticker (10) prepared thereby is shown in FIG. 2. The transfer-printing sheet or sticker (10) comprises a substrate (12) having a binder (14) on one surface thereof, a transparent polyester (PET) (16) disposed on said binder (14) thus forming a base for printing, a layer of ink (18) of a pattern and/or characters being printed on said PET layer (16), a second binder (20) applied onto said PET layer (16), and a transferring paper (22) being disposed on said second binder (20), wherein, before said second binder (20) is applied onto the PET layer (16) after printing, said PET layer (16) and said binder (14) are cut off along the outlines of the pattern and/or characters thereon with a cutting instrument, and then the edge portion of which has been cut off and uncovered by said ink (18) is separated from the others.
There is, however, a drawback of the conventional transfer-printing sheet or sticker (10). Since, after said ink (18) is printed onto said PET layer (16), said PET layer (16) must be cut along the outlines of the pattern and/or characters thereon with a cutting instrument before proceeding to the following steps, and irregular edges form at the boundary of the pattern and/or characters. Therefore, it is possible that, when transfer-print a pattern and/or characters to a receiver on which the surface is uneven, irregular wrinkles are generated on the printed pattern or characters, and thus the integrated appearance and beauty of the receiver deteriorate. That is, they adversely affect the visual effect.
Moreover, in order to precisely cut the printed pattern or characters off of said PET layer (16), the cutting instrument must be specifically designed and produced. The finer the printed pattern or characters, the more difficult the production of the cutting instruments. The size and replacement of the cutting instrument are also limited by mechanical automation. After cutting, the edge portion of the PET layer (16), which has no pattern and/or characters printed thereon, must be carefully peel off. Therefore, additional cost and time are inevitable with the conventional process. It is necessary to improve the conventional process in order to follow the trend of transfer-printing toward variety but limited quantities of products.